镧对硅纳米管生长的影响机制

The Growth Mechanism of Silicon Nanotube Modulated by Lanthanum

采用热蒸发法,在初始反应物硅(Si)及一氧化硅(SiO)混合粉末中加入镧(La)粉,能够成功地制备出硅纳米管.La粉作为一种特殊的气化调节剂,可以通过调节气化SiO的浓度来控制一维硅纳米材料的形貌,而且在最终的产物中并没有发现任何杂质.基于三相界面优先生长模型及氧化辅助生长理论来解释这种可控生长.采用透射电子显微镜(TEM)来分析产物形貌,并通过电感耦合等离子体原子发射光谱(ICP-AES)及X射线衍射(XRD)分析产物及剩余物成分.

Silicon nanotube was synthesized by a thermal evaporation technique with lanthanum in the source powder of silicon and silicon monoxide. There was no metal contamination detected in the final products. The growth of silicon nanotubes could be controlled by the concentration of vaporized silicon monoxide modulated by the quantity of lanthanum, which is theoretically discussed based on a preferential precipitation growth at three phase interfaces under the oxide-assisted condition~ Transmission electron microscopy （TEM）, inductively coupled plasma atomic emission spectrum （ICP-AES） and X-ray diffraction （XRD） were used to characterize the products and source residue.